Mike, congratulations on getting the water heater to start up.
Water heater switch - The switch is there to turn power on and off to the electric element. If it is working it will help out. Try to remember not to turn that on with no water in the tank, bad ju-ju happens...
What model refrigerator do you have? There should be a nameplate/sticker inside the door with model/serial number. See if you can find that nameplate and post a picture. Then we can look for the manual for the beast and see what is going on.
Or you can look here on the Dometic site Operation & Installation Manuals - Dometic
Or google it, the Dometic site did not have my RM2652 listed, skipped over it, but "the google" found the manual and parts manual on other sites. For free... I saved them on my computer for reference, you never know when Mr Murphy will jump up and try to bite...
"What is the valve for under bed for fresh water tank. Is that a drain valve or the valve I open up when I hook water up to outside to fill the tank. and where is the fresh water drain valve."
That valve beside the tank under the bed is the drain valve, that is all it does. I would drain the tank and sanitize it and the fresh water system just for general purposes. Here is a link to a thread on the forum with suggestions as to how to do that, herk7769 posted a simple way to that there. Fresh Water Tank Sanitization
To fill the tank pop the cover and use your fresh water hose to fill, you might have to play with how fast the water flows to keep it from blowing out and soaking you. I took an old twist type garden nozzle and put a length of tubing on it that fits nicely down the fill line and stays put if I turn the water on just right. When I fill my tank I lift the bed up and watch the level rise, For normal travel to campgrounds with hookups I keep just above 1/3 tank on board. That way if we need to rinse a cup or wash hands for lunch I just turn the pump on and take care of business. Also reduces the excess weight I carry around. If you go camping without hookups that changes things, full tank, etc.
"I know where the Black and grey drain valves are but how do you drain the Galley??"
On my unit the galley tank is on the starboard (passenger) side aft of the rear wheels and just before the battery compartment. You kind of have to stand on your head or squat down real low to see the tank and drain valve. When I dump tanks that is the last one I pull. I dump the Black, then the Grey, then the Galley tank.
You should also see 2 little plastic pipe stubs sticking down around there with plugs installed. Those are the hot and cold water low point drains, you use those to drain water out of the lines when you winterize the coach. Just make sure you have the faucets open to let air into the lines and the water out.
Not bothering at all, I had a lot of help learning the RV life and enjoy helping out. Helps that I grew up with RVs in the family and worked as a lot rat/service tech at a dealership when I was in high school...
Chris in Virginia